Harvesting Costs Research Articles

Application of filamentous fungi in microalgae-based wastewater remediation for biomass harvesting and utilization: From mechanisms to practical application

The model of microalgae-based wastewater remediation for nutrient recovery and biomass production has been intensively studied, but high cost of biomass harvesting jeopardizes the industrial application of this model. To support the implementation of this model and the sustainable development, this work introduces the use of filamentous fungi in microalgae-based wastewater remediation for biomass harvesting and utilization. First, this work describes the research progresses of co-cultivation of fungi and microalgae and fungi-assisted algae harvesting. Second, mechanisms and key parameters of fungi-assisted microalgae harvesting are discussed. Third, an in-depth discussion of co-cultivating filamentous fungi and microalgae in wastewater for nutrient removal and biomass collection is provided. Fourth, this work introduces some high-value components, which are of importance to the economic benefits and industrial application of harvested algal-fungal biomass, in microalgae and filamentous fungi. By the end of this paper, some problems associated with the co-cultivation of algal-fungal consortia in wastewater and fungi-assisted microalgae harvesting are listed and potential solutions to these problems are proposed. It is expected that this work can help readers understand the achievements in the research of fungi-assisted microalgae and the importance of this novel model to biomass harvesting and utilization.

Assessment of the Working Performance of an Innovative Prototype to Harvest Hemp Seed in Two Different Conditions of Terrain Slope

After many decades when its cultivation was prohibited, hemp is regaining its position as one of the most versatile cultivated crops. Multiplication of monoecious hemp varieties requires manual male plants rouging to keep a high share of monoecious plants in the population. It forces relatively small multiplication fields usually oscillating around 5 ha, where the use of big harvesting machines is not economically feasible. The B-800 mower prototype for hemp panicles proved to be a good alternative to harvest seeds of tall fibrous hemp. The test results of the mower analyzed in this study show that although seed loss on a moderate slope (0.37%) was significantly higher than on a flat slope (0.13%), it was still much lower than in the case of harvesting hemp seed with a combined harvester. Moreover, the field efficiency of 93% is very satisfactory as it is reported for much bigger machines. Finally, the harvesting costs proved to be much lower than most of the machines used for harvesting hemp seed.

Contribution of Livelihoods to the Well-Being of Coffee-Growing Households in Southern Colombia: A Structural Equation Modeling Approach

Coffee cultivation is one of the main agricultural activities in Colombia, which increases the well-being of coffee-growing families. In order to determine the impact of coffee production, the capital endowment and well-being of coffee-growing families in the municipality of Pitalito, in the south of Colombia, were analyzed using the community capital index (CCI). Likewise, the relationships between the variables were identified through a Pearson correlation analysis, and the increase in well-being was identified and modeled by employing structural equations. The structural equation model showed a suitable fit to the data, indicated by the non-significant value of the χ2 statistic (p = 0.85), a high CFI (0.97), a low RMSEA (<0.001), a low stability index (0.23) and a low variance inflation factor (VIF = 1.42). At the capital level, political capital in synergy with social capital increased the well-being of coffee-growing families; meanwhile, capitals such as natural and physical-built capital did not have the greatest impact on well-being. Political capital variables such as the “possession of the coffee identification card” (CPI), as well as the variable “participates in the activities carried out by the community action board of the village” (PAC), increased by 9.9% and 8.66%, respectively, in the well-being of coffee-growing families measured by the CCI. The social capital variables that boosted the CCI were the benefits of the National Federation of Coffee Growers (FNC) (BFN, %V(variation): 8.32) and associativity (Aso, %V: 7.51). Other variables that make up human capital with high incidence in the CCI were family size (FSi) and the number of people who can read in the family (FLE) with a variation of 9.12% and 8.6%, respectively. However, other variables such as labor cost for disease management (CDM) and labor cost for harvesting (HCL) had no significant effect on the variation of the CCI. It was found that the level of well-being increases due to variables such as associativity and participation in grassroots organizations in the community, such as being a member of the National Federation of Coffee Growers, a quality represented by the possession of a coffee identification card that, in synergy with other variables, reduce inequality and poverty.

Productivity and Management of Renewable Resources: Why More Efficient Fishing Fleets Should Fish Less

This article analyses the effect of productivity improvements on optimal fisheries management. It is shown that when harvest costs are independent of resource stock and the stock is below its steady state level, then for any given stock it is optimal to reduce harvest levels in response to a productivity increase unless optimal harvest rate is already zero. If harvest costs are stock dependent this result is modified; for stock dependent harvest costs there exists an interval of stock sizes below the steady state where it is optimal to reduce the harvest rate for any given stock size whereas if the harvest rate is close to an economically optimal steady state it is optimal to increase the harvest rate.

Odpornost kmetij s prirejo mleka z različnimi prilagoditvami proizvodnega načrta

In this study, the resilience of farm production plan through different management adjustments was analyzed. For this purpose, a farm model based on mathematical programming was applied. Through organized workshops typical farms focusing on dairy production were defined through qualitative and quantitative classification. Data were obtained from various databases and expert assessments from the agricultural sector. Analysis of resilience was carried out for three of these typical dairy farms. Using the farm model, the production plan of each farm was reconstructed in the first step and then tested for possible deviations from the baseline. Gross margin was used as the main economic indicator. The results show that the typical farms have very different levels of efficiency and potential for improvement. Furthermore, it was found that all farms can achieve significantly higher gross margin only with improved feed quality, which indirectly leads to a lower need for purchased feed and consequently to lower variable costs and higher gross margin. The level of the latter is also significantly affected by the milk yield achieved, especially on larger farms. However, on smaller farms they can improve profitability more significantly by keeping dairy cows on pasture to a greater extent, which results in a reduction in harvesting costs.

Combine Harvester: Small Machine Solves Big Rice Harvesting Problem of Bangladesh

Bangladesh, a country with 87% of rural households that depend on agriculture and rice dominated diets (70%), engages the country’s food security. Therefore, there is strong advocacy for a mechanized paddy harvesting system for food security in South Asia, mainly Bangladesh. Some harvesting machinery is available; however, the precise roles of a combine harvester during this process are little. This study attempts to understand the consequences of combining harvesters for paddy harvesting and compare them with hand harvesting. For comparison of field performance of combine harvester with traditional harvesting, the experiment was conducted at Gazipur District, Bangladesh, in 2016. Results showed that the labor required for harvesting unit area 283, 15 and 9.87 man-h∙ha−1 for T1 (Sickle + Head carry + Beating + Kula), T2 (Reaper + Trolley carry + Close drum thresher + winnower), T3 (Combine harvester) system, respectively. Likewise, the harvesting costs were 1.84 (T2) and 2.5 (T1) times higher than the combine harvester (T3). Also, the postharvest loss can be saved 1.84%, to use combine harvester over manual harvesting of paddy. The above result revealed that the semi-mechanized and mechanized harvesting system is a time, labor and cost-saving system; however, the manual reaping system is concerned with more postharvest losses (3.09%). This study highlights the importance of combine harvester; however, further research is required in other places with large and mini-combine harvesters under diverse cropping areas and to test a combine harvester’s detailed potentiality.

Sugarcane Transportation and Harvesting Cost in Punjab

Sugarcane is one of the most important commercial crops of Punjab. Being an annual crop, the costs incurred in raising sugarcane were comparatively higher than other field crops. Due to its bulky nature, farmers spent hugely on harvesting and transporting cane to sugar mills. A field survey comprising 200 growers was undertaken in major cane growing districts of the state. The results revealed the selling of a major share of a marketable surplus of cane to the sugar mills with negligible quantity to jaggery manufacturers. The cane harvesting/ chopping was under a contractual system, including loading for transport to sugar mills. The harvesting cost of sugarcane worked out at 15071, while the transportation cost was 3479 per acre. Problems encountered by the cane growers included; transportation bottlenecks due to heavily loaded vehicles, based distribution of purchase slips by the sugar mills favouring politically sound/ connected growers and long waiting periods in the vicinity of sugar mills during the marketing process.

Shining a Light on Wastewater Treatment with Microalgae.

Microalgae can produce biofuels, nutriceuticals, pigments and many other products, but commercialization has been limited by the cost of growing, harvesting and processing algal biomass. Nutrients, chiefly nitrogen and phosphorus, are a key cost for growing microalgae, but these nutrients are present in abundance in municipal wastewater where they pose environmental problems if not removed. This is not a traditional review article; rather, it is a fact-based set of suggestions that will have to be investigated by scientists and engineers. It is suggested that if microalgae were grown as biofilms rather than as planktonic cells, and if internal illumination rather than external illumination were employed, then the use of microalgae may provide useful improvements to the wastewater treatment process. The use of microalgae to remove nutrients from wastewater has been demonstrated, but has not yet been widely implemented due to cost, and because microalgae derived from wastewater treatment has not yet been demonstrated as a commercial source for value-added products. Future facilities are likely to be called Municipal Resource Recovery Facilities as wastewater will increasingly be viewed as a resource for water, biofuels, fertilizer, monitoring public health and value-added products. Advances in photonics will accelerate this transition.

Development of Tractor Front Mounted Harvester for Finger Millet

Finger millet crop is important minor millet, which can serve as both food and fodder. Manual harvesting of finger millet involves harvesting earhead and stalk separately which is labor intensive. Hence, the study aimed to design and develop a harvester for finger millet to remove drudgery in harvesting and to achieve a low cost of harvesting. The important crop and machine parameters influencing the harvesting of finger millets were identified for the most prominent variety of CO (Ra) 14 in finger millet. A prototype finger millet harvester was developed and the effect of a machine and operational parameters were evaluated in terms of header loss at different levels of a rotational speed of reel 30, 35 and 40 revolutions per minute (rpm), 35, 40 and 45 cm mounting height of reel and forward speed 1.6, 2.68, and 3.48 km/h. The performance of the harvest was found satisfactory. Comparing the best combinations of machine and operational parameters, the minimum header loss of 1.25 per cent was achieved at the combination of 30 rpm rotational speed of reel, 40 cm mounting height of reel and 2.68 km/h forward speed.

Maximum principle for the optimal harvesting problem of a size-stage-structured population model

<p style='text-indent:20px;'>The optimal harvesting of biological resources, which is directly relevant to sustainable development, has attracted more attention. In this paper, we first prove the existence and uniqueness of generalized solution of a size-stage-structured population model while the optimal harvesting effort is discontinuous. Next, we demonstrate the existence of the optimal harvesting policy. Further, based on the idea of the Pontryagin's maximum principle of the optimal control problem in ordinary differential equations, we derive the maximum principle describing the optimal control. Finally, the dynamical behavior of the population is simulated by solving the corresponding optimality system numerically with an algorithm based on the method of backward Euler implicit finite-difference approximation. The numerical simulations indicate harvesting activity will reduce the quantity of the population and that increasing harvesting cost will result in less adult harvested. This provides guideline of implementing harvesting tactic to guarantee the persistence of the population.</p>

Test and Evaluation of the Factors Affecting on the Freshly Harvested Peanut Threshing Machine Performance

Abstract Peanut is an important produce in the global food chain because of their high-quality oil and protein content. Due to the significant value of its production in Iran, a threshing machine was developed for high-quality harvesting, to reduce harvesting costs and labor effort. In the course of a number of field experiments to evaluate the performance of the machine, the rotational speed of the thresher was adopted at three levels of 150, 200, and 300 rpm. Other experimental factors included the distance of the concave from the thresher (2, 6, and 8 cm) and the product feeding rate of 750, 850, and 950 kg·h−1. Regarding the measurements, the threshing efficiency, the separation rate, and the percentage of the crushed product were calculated and evaluated. The results revealed that as the rotational speed of the thresher, the increment feeding rate of the product and the distance between the thresher and the concave grate increased, the thresher efficiency decreased. The maximum threshing efficiency of 95% was obtained at a rotational speed of 150 rpm and a distance of 2 cm. Also, with increasing the rotational speed of 300 rpm and a distance of 8 cm, the threshing efficiency decreased to 75%. The separation rate decreased intensely as the distance between the thresher and the concave increased. In addition, the separation rate decreases with increasing rotational speed of the thresher. At a rotational speed of 150 rpm and a distance of 2 cm, the separation rate was 96%, but the separation rate decreased to 76% as rotational speed increased to 300 rpm and distance increased to 8 cm. With increasing rotational speed and feeding rate, the percentage of crushed pods increased. The maximum of 16% was obtained at a rotational speed of 300 rpm, a feeding rate of 950 kg·h−1 and a distance of 2 cm.

Study of The Behavioral Aspects Related to The Production and Marketing of Balady Lime Among Farmers at some Villages of El-Tahrier District at El-Beheira Governorate

This research is mainly aimed to study the behavioral aspects related to the production and marketing of Balady Lime among farmers at some villages of El-Tahrier District, El-Beheira Governorate, The data were collected using a questionnaire with a personal interview, of 158 respondents' farmers which were randomly selected from the farmers growing Balady Lime at the village of Al-Maraka, El-Tahrier District, and represent about 14% of total holders, during the months of November and December 2020. The data were downloaded and scheduled, using statistical methods such as percentages, means, standard deviation, Pearson's simple correlation coefficient and frequency distribution tables were used to explain and interpret the results. The most important findings of the research showed that: - (32.2%) of the respondents had a lack of knowledge level ranging between low and medium according to the technical recommendations concerned with the production and marketing of the Balady Lime, while (54.4%) of them had a low and moderate level of total implementation of the technical recommendations concerned with the production and marketing of the Balady Lime. - A progressive and significant correlation between the respondents' knowledge level as a first dependent variable and (Age, area of ​​agricultural land, Balady Lime grown area, years of experience in Balady Lime farming), and the degree of the respondents' implementation to the technical recommendations concerned with the production and marketing of the Balady Lime as a second dependent variable and (Age, area of ​​agricultural land, Balady Lime grown area, years of experience in Balady Lime farming). - The most important problems facing the Balady Lime respondents farmers was the high prices of agricultural inputs, the spread of Gummosis disease, the dangerous and rapid spread of various insect, fungal and viral pests, the high costs of treatment disease and insect injuries, the low price of the crop, the control by traders of supply prices, the high cost of harvesting and the lack of availability of manufacturing.

Assessing the Economic Viability of the Mechanized Removal of Understory Beech during a Shelterwood Harvest

Abstract Beech bark disease is a pathogenic complex that has been spreading throughout the American beech’s range since the 1800s. A litany of negative consequences have manifested from the infestation of this disease, many of which deteriorate the ecological functions of forestland. This case study sought to analyze the cost structure for removing a recalcitrant beech understory via mechanized shelterwood harvesting. High-resolution data regarding the day-to-day operation of harvesting equipment was collected using daily production journals. Interviews were conducted with the logging company owner and maintenance supervisor to gather additional information required to calculate machine costs, overhead, job specific costs, and trucking costs. The yield from this harvest was 527 metric tonnes of sawtimber and 4,893 tonnes of clean chips. The total harvesting cost equated to $4,651/ha, with the cost attributed to removing beech at $204/ha. Despite the additional cost of beech removal, the logger generated a total profit of $5,965 and a return on investment of 7.5%, allowing us to conclude that mechanized harvesting can be a viable beech removal strategy given the forest stocking and market conditions that are in place.

Costs of semi-mechanized forest harvest of Tectona grandis L. F. in the brazilian Amazon

The objective of this study was to identify the harvesting system applied for Tectona grandis and its adaptations to describe the harvesting activities, characterization of the machines used and costing. The costs raised in this work were divided by activity and cost component. The work resulted in the description of the forest felling, this being carried out using three chainsaws of the Stihl brand, model MS 660 with the chainsaw teams adjusted to the scheme (1+1), an operator and a helper. As an adaptation of the system, the extraction was performed from inside the field to the storage yard, and executed with a Massey Ferguson tractor, model MF 275, of medium size with high axle, 4x2 rear-wheel drive, 75 horsepower and torque of approximately 28 kgfm adapted with a winch and use of drag chain, a tractor driver and two assistants. Labor was the most expensive cost, representing 80.82% of the total harvest cost. Gross profit per hectare was R$ 15,525.00, of which 30.76% was consumed by operating costs, being labor the most significant. Selling raw logs, as it was performed in this work, significantly decreases the price of the cubic meter.

Strip Clearcutting Drives Vegetation Diversity and Composition in the Moso Bamboo Forests

Abstract Strip clearcutting of Moso bamboo forests in southern China has seen increasing interest as a way of reducing harvesting costs. Previous research has shown that cutting influences the overstory structure and drives changes in the microclimate and soil properties. However, the effects of strip cutting on understory vegetation diversity and composition remain unclear. To better understand the influence of cutting on the understory vegetation, this study compares sites under natural restoration after cut and uncut sites in the Moso bamboo forest. We selected plots that were cut in 2019 (C19) and 2017 (C17), as well as unharvested plots as controls (CK). The results showed that strip clearcutting increased the understory vegetation richness and diversity, and a significant difference (A = 0.23, P = 0.001) existed in the composition of the vegetation between the three treatments. Furthermore, the decrease of soil total phosphorus and total potassium content resulted in the difference in undergrowth vegetation distribution and composition between the uncut plots and the cut plots. Our results suggest that strip clearcutting may not be harmful to biodiversity on a local scale in the Moso bamboo forest.

Effects of illumination time on biological community of algal-bacterial granules and lipid content

Synthetic wastewater was used to culture granular sludge for 21 weeks at three sequencing batch reactor activated sludge process (SBR) under different photoperiods. The growth of algae changed granular oxygen distribution, which affected the composition of microbial communities. Different photoperiods were able to alter the formation of granular sludge and the microbial community granules. In short photoperiod (12 h/d) sludge could generate symbiotic algae-bacteria granules in the SBR. By contrast, the long photoperiod (24 h/d) promotes the growth of algae and Ascomycota early, and then inhibits algae, especially chlorophyta (only 1.18%). In the end, algae-bacteria-fungi granules were formed in long photoperiod (LP). By GC-MS and model calculation, the lipid content of algae-bacteria granules was 33.71% more than that of pure aerobic granular sludge. However, the proportion of unsaturated fatty acids in algae-bacteria granules was as high as 43%, resulting in the quality of biodiesel prepared from algae-bacteria granule being slightly worse than that prepared from pure aerobic granular sludge. But both of them were better than biodiesel prepared from pure algae. The biodiesel content of algae-bacteria granule in short photoperiod (SP) and LP were 68.79 and 70.66 mg/g, respectively, which was better than that of pure aerobic particles (52.30 mg/g). Therefore, the formation of algae-bacteria granules is an effective way to remove nutrients and reduce harvesting costs.

Mechanized Blueberry Harvesting: Preliminary Results in the Italian Context

This study reports some preliminary results on mechanical blueberry harvesting for the fresh market of cv. Cargo® in the Piedmont region (northwest Italy). The investigated area is one of the most productive areas of Italy, which specializes in fresh blueberry production. The automatization of harvesting operations could represent a competitive advantage for the area’s blueberry supply chain but could limit the quality of fresh-picked berries. A prototype machine and a commercial harvester (Easy Harvester®) were compared with manual picking, considering the harvesting efficiency, labor productivity, harvesting cost and farm rentability. In this context, the labor cost for manual harvesting exceeds EUR 2.00 per kg of saleable product. The prototype allowed a 39% cost reduction, and the Easy Harvester® reduced it by about half. Nevertheless, these positive performances do not consider the reduction in the net sale price of EUR 0.40 due to the selection costs in the warehouse. In this study, we highlight that the transition to mechanical harvesting requires the transformation of several farming and packhouse operations, such as new crop varieties, field configurations and cultivation techniques. However, a possible technical improvement of the Easy Harvester® could represent an opportunity for Italian farms in the planning of berry production and marketing, involving all of the supply chain actors. Further research on the use of mechanization in the sector must continue and be supported.

Endogenous catch per unit effort and congestion externalities between vessels in a search‐matching model: Evidence from the French Guiana shrimp fishery

AbstractThis paper aims at explaining the recent rise in profits in the French Guiana shrimp fishery (FGSF) despite the overall fall in activity observed between 1990 and 2009. We develop a stochastic search‐matching version of the usual Cobb–Douglas bioeconomic fishery model. In this version catch per unit effort becomes endogenous, decreasing in the ratio of empty vessels to escaped fish, which we call “anthropic pressure” and which is determined by standard profit maximization. We first estimate the stochastic harvest function, which exhibits nearly constant returns to scale. We then show that a decrease in equilibrium anthropic pressure and congestion between vessels may be more than compensated by the consecutive rise in catch per unit effort. This leads to a fall in average harvesting costs and thus, to a rise in profits. In addition, we identify the condition under which a search‐matching fishery, working under open access, could reach a maximum economic yield equilibrium, which corresponds to a very particular case. Finally, the model makes it possible to evaluate the actual catch per unit effort and explain how the FGSF changed over the period considered with the help of the open access and maximum economic yield frameworks.

Application of 1.0-μm macroporous hollow fiber membrane for prevention of membrane fouling and enhancement of permeate flux in algae harvesting

We challenged to introduce macroporous membrane for algae harvesting with a permeate flux of 166 L m−2 d−1 to achieve significant reduction of harvesting cost. Analysis of the dissolved organic matter in the supernatant of cultures of the green alga, Coccomyxa sp. strain Obi, detected a scarce amount of hydrophilic macromolecules, which can be membrane fouling agents. The continuous filtration with a macroporous membrane achieved a 30-fold concentration of algal cells from 800 mg biomass/L to 24,000 mg biomass/L with a harvesting efficiency of 100%. Most of previous studies on the membrane filtration for harvesting microalgae merely utilized microfiltration membranes developed for wastewater treatment. However, the use of a membrane of the largest pore size that microalgal cells cannot seep through will result in slower fouling, higher flux, and a great reduction of harvesting cost.

ESPDS

In this paper, we introduce a Microsoft Excel Workbook containing the software Equipment Selection Problem DS (ESPDS) that recognizes the special structure of the equipment selection problem. The ESPDS approach is based on the context of the Brazilian forestry sector using detailed equipment maintenance schedules. No special restrictions are needed on cost inputs over time or technologies. The output is an equipment schedule that can be used to project equipment investment needs, operational costs, and tree harvesting costs. ESPDS can be applied to support companies and contractors in order to choose the best option for their operations, as well as to achieve better equipment purchase agreements. We will show how ESPDS will also be useful in providing longer term estimates of production costs. The sensitivity analysis shows how different inputs and maintenance polices can affect the best alternative. A numerical example is included considering the entrance of a specific technology that increases the equipment productivity in order to examine whether it can change the solution. ESPDS is intuitive, flexible, and easy to calculate. Although designed for the forestry industry, the approach is readily transferable to other sectors. ESPDS may be found on the web at the following URL: <a target="_blank" rel="nofollow" href="https://www.researchgate.net/publication/350811380_ESPDS_workbook">https://www.researchgate.net/publication/350811380_ESPDS_workbook</a>.